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kernel-fxtec-pro1x/arch/arm/include/asm/system.h
Russell King bac4e960b5 [ARM] barriers: improve xchg, bitops and atomic SMP barriers 
Mathieu Desnoyers pointed out that the ARM barriers were lacking:

- cmpxchg, xchg and atomic add return need memory barriers on
  architectures which can reorder the relative order in which memory
  read/writes can be seen between CPUs, which seems to include recent
  ARM architectures. Those barriers are currently missing on ARM.

- test_and_xxx_bit were missing SMP barriers.

So put these barriers in.  Provide separate atomic_add/atomic_sub
operations which do not require barriers.

Reported-Reviewed-and-Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-05-28 19:39:27 +01:00

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#ifndef __ASM_ARM_SYSTEM_H
#define __ASM_ARM_SYSTEM_H
#ifdef __KERNEL__
#define CPU_ARCH_UNKNOWN 0
#define CPU_ARCH_ARMv3 1
#define CPU_ARCH_ARMv4 2
#define CPU_ARCH_ARMv4T 3
#define CPU_ARCH_ARMv5 4
#define CPU_ARCH_ARMv5T 5
#define CPU_ARCH_ARMv5TE 6
#define CPU_ARCH_ARMv5TEJ 7
#define CPU_ARCH_ARMv6 8
#define CPU_ARCH_ARMv7 9
/*
* CR1 bits (CP#15 CR1)
*/
#define CR_M (1 << 0) /* MMU enable */
#define CR_A (1 << 1) /* Alignment abort enable */
#define CR_C (1 << 2) /* Dcache enable */
#define CR_W (1 << 3) /* Write buffer enable */
#define CR_P (1 << 4) /* 32-bit exception handler */
#define CR_D (1 << 5) /* 32-bit data address range */
#define CR_L (1 << 6) /* Implementation defined */
#define CR_B (1 << 7) /* Big endian */
#define CR_S (1 << 8) /* System MMU protection */
#define CR_R (1 << 9) /* ROM MMU protection */
#define CR_F (1 << 10) /* Implementation defined */
#define CR_Z (1 << 11) /* Implementation defined */
#define CR_I (1 << 12) /* Icache enable */
#define CR_V (1 << 13) /* Vectors relocated to 0xffff0000 */
#define CR_RR (1 << 14) /* Round Robin cache replacement */
#define CR_L4 (1 << 15) /* LDR pc can set T bit */
#define CR_DT (1 << 16)
#define CR_IT (1 << 18)
#define CR_ST (1 << 19)
#define CR_FI (1 << 21) /* Fast interrupt (lower latency mode) */
#define CR_U (1 << 22) /* Unaligned access operation */
#define CR_XP (1 << 23) /* Extended page tables */
#define CR_VE (1 << 24) /* Vectored interrupts */
#define CR_EE (1 << 25) /* Exception (Big) Endian */
#define CR_TRE (1 << 28) /* TEX remap enable */
#define CR_AFE (1 << 29) /* Access flag enable */
#define CR_TE (1 << 30) /* Thumb exception enable */
/*
* This is used to ensure the compiler did actually allocate the register we
* asked it for some inline assembly sequences. Apparently we can't trust
* the compiler from one version to another so a bit of paranoia won't hurt.
* This string is meant to be concatenated with the inline asm string and
* will cause compilation to stop on mismatch.
* (for details, see gcc PR 15089)
*/
#define __asmeq(x, y) ".ifnc " x "," y " ; .err ; .endif\n\t"
#ifndef __ASSEMBLY__
#include <linux/linkage.h>
#include <linux/irqflags.h>
#define __exception __attribute__((section(".exception.text")))
struct thread_info;
struct task_struct;
/* information about the system we're running on */
extern unsigned int system_rev;
extern unsigned int system_serial_low;
extern unsigned int system_serial_high;
extern unsigned int mem_fclk_21285;
struct pt_regs;
void die(const char *msg, struct pt_regs *regs, int err)
__attribute__((noreturn));
struct siginfo;
void arm_notify_die(const char *str, struct pt_regs *regs, struct siginfo *info,
unsigned long err, unsigned long trap);
void hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int,
struct pt_regs *),
int sig, const char *name);
#define xchg(ptr,x) \
((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
extern asmlinkage void __backtrace(void);
extern asmlinkage void c_backtrace(unsigned long fp, int pmode);
struct mm_struct;
extern void show_pte(struct mm_struct *mm, unsigned long addr);
extern void __show_regs(struct pt_regs *);
extern int cpu_architecture(void);
extern void cpu_init(void);
void arm_machine_restart(char mode, const char *cmd);
extern void (*arm_pm_restart)(char str, const char *cmd);
#define UDBG_UNDEFINED (1 << 0)
#define UDBG_SYSCALL (1 << 1)
#define UDBG_BADABORT (1 << 2)
#define UDBG_SEGV (1 << 3)
#define UDBG_BUS (1 << 4)
extern unsigned int user_debug;
#if __LINUX_ARM_ARCH__ >= 4
#define vectors_high() (cr_alignment & CR_V)
#else
#define vectors_high() (0)
#endif
#if __LINUX_ARM_ARCH__ >= 7
#define isb() __asm__ __volatile__ ("isb" : : : "memory")
#define dsb() __asm__ __volatile__ ("dsb" : : : "memory")
#define dmb() __asm__ __volatile__ ("dmb" : : : "memory")
#elif defined(CONFIG_CPU_XSC3) || __LINUX_ARM_ARCH__ == 6
#define isb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" \
: : "r" (0) : "memory")
#define dsb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
: : "r" (0) : "memory")
#define dmb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" \
: : "r" (0) : "memory")
#elif defined(CONFIG_CPU_FA526)
#define isb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" \
: : "r" (0) : "memory")
#define dsb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
: : "r" (0) : "memory")
#define dmb() __asm__ __volatile__ ("" : : : "memory")
#else
#define isb() __asm__ __volatile__ ("" : : : "memory")
#define dsb() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
: : "r" (0) : "memory")
#define dmb() __asm__ __volatile__ ("" : : : "memory")
#endif
#ifndef CONFIG_SMP
#define mb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)
#define rmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)
#define wmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
#else
#define mb() dmb()
#define rmb() dmb()
#define wmb() dmb()
#define smp_mb() dmb()
#define smp_rmb() dmb()
#define smp_wmb() dmb()
#endif
#define read_barrier_depends() do { } while(0)
#define smp_read_barrier_depends() do { } while(0)
#define set_mb(var, value) do { var = value; smp_mb(); } while (0)
#define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t");
extern unsigned long cr_no_alignment; /* defined in entry-armv.S */
extern unsigned long cr_alignment; /* defined in entry-armv.S */
static inline unsigned int get_cr(void)
{
unsigned int val;
asm("mrc p15, 0, %0, c1, c0, 0 @ get CR" : "=r" (val) : : "cc");
return val;
}
static inline void set_cr(unsigned int val)
{
asm volatile("mcr p15, 0, %0, c1, c0, 0 @ set CR"
: : "r" (val) : "cc");
isb();
}
#ifndef CONFIG_SMP
extern void adjust_cr(unsigned long mask, unsigned long set);
#endif
#define CPACC_FULL(n) (3 << (n * 2))
#define CPACC_SVC(n) (1 << (n * 2))
#define CPACC_DISABLE(n) (0 << (n * 2))
static inline unsigned int get_copro_access(void)
{
unsigned int val;
asm("mrc p15, 0, %0, c1, c0, 2 @ get copro access"
: "=r" (val) : : "cc");
return val;
}
static inline void set_copro_access(unsigned int val)
{
asm volatile("mcr p15, 0, %0, c1, c0, 2 @ set copro access"
: : "r" (val) : "cc");
isb();
}
/*
* switch_mm() may do a full cache flush over the context switch,
* so enable interrupts over the context switch to avoid high
* latency.
*/
#define __ARCH_WANT_INTERRUPTS_ON_CTXSW
/*
* switch_to(prev, next) should switch from task `prev' to `next'
* `prev' will never be the same as `next'. schedule() itself
* contains the memory barrier to tell GCC not to cache `current'.
*/
extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *);
#define switch_to(prev,next,last) \
do { \
last = __switch_to(prev,task_thread_info(prev), task_thread_info(next)); \
} while (0)
#if defined(CONFIG_CPU_SA1100) || defined(CONFIG_CPU_SA110)
/*
* On the StrongARM, "swp" is terminally broken since it bypasses the
* cache totally. This means that the cache becomes inconsistent, and,
* since we use normal loads/stores as well, this is really bad.
* Typically, this causes oopsen in filp_close, but could have other,
* more disasterous effects. There are two work-arounds:
* 1. Disable interrupts and emulate the atomic swap
* 2. Clean the cache, perform atomic swap, flush the cache
*
* We choose (1) since its the "easiest" to achieve here and is not
* dependent on the processor type.
*
* NOTE that this solution won't work on an SMP system, so explcitly
* forbid it here.
*/
#define swp_is_buggy
#endif
static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
{
extern void __bad_xchg(volatile void *, int);
unsigned long ret;
#ifdef swp_is_buggy
unsigned long flags;
#endif
#if __LINUX_ARM_ARCH__ >= 6
unsigned int tmp;
#endif
smp_mb();
switch (size) {
#if __LINUX_ARM_ARCH__ >= 6
case 1:
asm volatile("@ __xchg1\n"
"1: ldrexb %0, [%3]\n"
" strexb %1, %2, [%3]\n"
" teq %1, #0\n"
" bne 1b"
: "=&r" (ret), "=&r" (tmp)
: "r" (x), "r" (ptr)
: "memory", "cc");
break;
case 4:
asm volatile("@ __xchg4\n"
"1: ldrex %0, [%3]\n"
" strex %1, %2, [%3]\n"
" teq %1, #0\n"
" bne 1b"
: "=&r" (ret), "=&r" (tmp)
: "r" (x), "r" (ptr)
: "memory", "cc");
break;
#elif defined(swp_is_buggy)
#ifdef CONFIG_SMP
#error SMP is not supported on this platform
#endif
case 1:
raw_local_irq_save(flags);
ret = *(volatile unsigned char *)ptr;
*(volatile unsigned char *)ptr = x;
raw_local_irq_restore(flags);
break;
case 4:
raw_local_irq_save(flags);
ret = *(volatile unsigned long *)ptr;
*(volatile unsigned long *)ptr = x;
raw_local_irq_restore(flags);
break;
#else
case 1:
asm volatile("@ __xchg1\n"
" swpb %0, %1, [%2]"
: "=&r" (ret)
: "r" (x), "r" (ptr)
: "memory", "cc");
break;
case 4:
asm volatile("@ __xchg4\n"
" swp %0, %1, [%2]"
: "=&r" (ret)
: "r" (x), "r" (ptr)
: "memory", "cc");
break;
#endif
default:
__bad_xchg(ptr, size), ret = 0;
break;
}
smp_mb();
return ret;
}
extern void disable_hlt(void);
extern void enable_hlt(void);
#include <asm-generic/cmpxchg-local.h>
/*
* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
* them available.
*/
#define cmpxchg_local(ptr, o, n) \
((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
(unsigned long)(n), sizeof(*(ptr))))
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
#ifndef CONFIG_SMP
#include <asm-generic/cmpxchg.h>
#endif
#endif /* __ASSEMBLY__ */
#define arch_align_stack(x) (x)
#endif /* __KERNEL__ */
#endif
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